The present invention relates to shoes, and more particularly to sports shoes having outer soles with sockets for spikes or cleats.
Modern footwear is typically comprised of a shoe upper which is attached to some or all of an inner sole, a mid-sole and an outer sole.
The details of the attachment of these components are well known in the art and can include cementing and/or stitching. Particularly with so-called "welt" construction, great care is required in the alignment of the components to produce a functional and aesthetically pleasing shoe. To lessen the care required, raw outer soles are typically oversized compared to the mid-sole so that some eccentricity or offset between the outer sole and the mid-sole is permissible during the manufacturing step of attaching the outer sole to the mid-sole. The use of an oversized outer sole, while lessening the care required to align the outer sole to the mid-sole, results in the addition of an extra step in the manufacturing process to trim the excess material after attachment of the outer sole. In addition, even with the use of an oversized outer sole, only a small amount of eccentricity can be accommodated.
For many years, the highest quality golf shoes have been made utilizing welt construction techniques. Such shoes employed nail-type spikes which were threaded into sockets carried by a plate mounted on the hidden side of the outer sole. The rigidity of such a plate adversely affected the flexibility of the sole. Furthermore, to avoid the feeling of a "lump" in the sole due to the plate, the upper surface of the outer sole was either very thick so that the plate could be mounted in a cavity formed therein, or else the upper surface of the outer sole was covered with filler material to raise the level to that of the plate.
Recently, a growing trend has developed away from the use of metal spikes, toward the use of disc-like, softer spikes which do less damage to the putting greens. Such spikes often utilize the same threaded mounting as did traditional metal spikes, and can be directly substituted in the threaded sockets supported on a common plate carried by the outer sole. New forms of sockets have been developed to accommodate further developments in such softer spikes, thereby eliminating the need for a metal plate, but nevertheless failing to overcome two long-standing deficiencies.
First, the support structure for the sockets, whether in the form of a molded web or molded individual housings, presents a thickness of relatively rigid structure which is thicker than the ideal nominal thickness of the outer sole. This differential will, if not accommodated, induce discomfort in the user, and if accommodated in the traditional manner, requires the extra cost associated with increasing the thickness of the sole, or using filler material to bring the upper surface of the sole even with the plate or housing projection. Secondly, despite improvements in the efficiency of manufacturing techniques, a laborer, rather than automated equipment, is typically required to accurately locate the outer sole onto the mid-sole, so that the outer sole can be attached thereto by sewing and/or adhesive. This locating step is not as easy as might appear at first glance, because the outer sole and mid-sole are slightly oversized during construction and there is no structural or visual cue as to correct alignment. The laborer must, in essence, position the outer sole against the inner sole until an essentially uniform overlap at the edges is evident, and maintain this overlap as the shoe is placed into a sewing machine (for stitching) or a heat press (for curing adhesive). To assist a laborer in this regard, for each size of shoe, a particular size mid-sole and a particular size outer sole are required.